Abstract

We report two zinc complexes of molecular formulae
[ZnCl
2
(Mes
-
BIAO)]
2
(
3
)
and
[ZnCl
2
(Dipp
-
BIAO)]
2
(
4
) ( Mes = Mesityl, Dipp
= 2,6
-
diisopropylphenyl) of rigid unsymmetrical
bidentate iminoacenapthenone ligands (Mes
-
BIAO) (
1
) and Dipp
-
BIAO) (
2
). The zinc complexes
3
and
4
can be achieved by the reaction of ZnCl
2
and neutral [
N
-
(mesityl)
-
iminoacenapthenone] (
1
) and [
N
-
(2,6
-
diisopropylphenyl)
-
iminoacenapthenone] ligand (
2
) respectively in dichloromethane at ambient
temperature. The solid state structures of the complexes
3
and
4
were established by single crystal X
–
ray
diffraction analysis. In the solid state structures, bo
th the complexes are dimeric in nature. In complexes
3
and
4
, each of the zinc coordination polyhedron is formed by the ligation of imine nitrogen, carbonyl
oxygen atoms of the ligand
1
and
2
respectively along with three chlorine atoms. Out these three ch
lorine
atoms, two are

2
bridged with adjacent zinc atom to form the dimer. Thus overall zinc atom is penta
-
coordinated and the geometry can be best described as a distorted trigonal bipyramidal or a distorted
square pyramidal.